Excellent Electrochromic Properties of Ti4+-Induced Nanowires V2O5 Films

Ti4+-doped V2O5 films with nanowires on top and a dense, long nanorod layer on the bottom were successfully fabricated using the spin-coating route. During the electrochromic cycling, charge transfer resistance (Rct) decreases while ion-diffusion ability (KΩ) rapidly drops in the first ten cycles and then levels off. Low Rct and morphology of nanowires collaboratively improved the electrochromic behavior of Ti4+-doped V2O5 films by enhancing the charge transfer speed and minimizing polarization and dissolution. The obtained Ti4+-doped V2O5 film shows better electrochromic properties than the undoped V2O5 film, with a coloration efficiency (CE) of 34.15 cm2/C, coloration time of 9.00 s, and cyclic retention of 82.6% at cycle 100. In contrast, the corresponding values for the undoped V2O5 film were 23.57 cm2/C, 13.16 s, and 43.6%.